Collapsible die for forging crankshafts



Sept. Z9, 1953 c. A. BRAUCHLER COLLAPSIBLE DIE FOR FORGING CRANKSHAFTS 5 Sheets-Sheet l Filed Deo. 27, 1947 Sept. 29, 1953 l c. A. BRAUCHLER 2,653,373

COLLAPSIBLE DIE FOR FORGING cRANKsHAFTs Filed Dec. 27, 1947 5 Sheets-Sheet 2 :inventor Gttomegs Sept. 29, 1953 c. A. BRAUcHLl-:R

COLLAPSIBLE DIE FOR FORGNG CRANKSHAFTS 5 Sheets-Sheet 5 Filed Dec. 27, 1947 noentor ptt {f7/mm 176g@ Gttomegs Sgpt. 29, 195.3 c. A. BRUCHLER 2,653,373

COLLAPSIBLE DIE FOR FORGING CRANKSHAFTS Filed Deo. 27, 1947 5 Sheets-Sheet 4 EIT"- f E nventor i Ulzarlesrwuclzier E am fri Gttornegs sept. 29, 1953 c. A. BRAUCHLER 2,653,373

COLLPSIBLE DIE FOR FORGING CRANKSHAFTS BWM Mgg Gttornegs Patented Sept. 29, 1953 UNITED STATES PATENT" GFFICE ooLLArsILE- DIE Fon rondine cnANKsHAFTs Charles A. Brauchler, Canton, Ghio Application December 27, 1947, Serial. No. 794,159

4 Claims. l

The invention relates to the manufacture of crankshafts and more particularly to collapsible dies for forging a complete crankshaft to nshed shape in a single forging operation.

In the manufacture of `crankshafts under present practice it is customary to either forge the entire crankshaft flat, that is with all of thethrows or cranks located in the same plane, after which the main bearing portions of the crankshaft are axially twisted to position the various throws or cranks at the desired relative angle to. each other; or the several throws or cranks are separately forged and then the several separate throws or cranks are welded together at theiry ends to form the complete crankshaft.

There are certain objections to bothvv of these methods. The twisting of the main bearing portions of the crankshaft is objectionable as it' sets up strains and stresses in the metal whichv tend to weaken the crankshaft at these points. Also, the large dies required for forging the entire crankshaft at, are very expensive to produce, especially in the manufacture of very large crankshafts such. as are used in largey diesel engines for railroad locomotives, marine use and the like,V and. since these dies are subjected to excessive impact or pressure in the forging operations, thcdies are frequently cracked or broken.

And in the other method, where the. throwsv or cranks are separately formed and then welded together, the welding operations are slow, expensive and not entirely satisfactory, and change' the structure of the metal at these points.

It is therefore an object of the present invention to generally improve and simplify the manufacture of crankshafts, so as to eliminate the objections and disadvantages of present practice so as to produce a superior crankshaft forging at considerably less expense and in a shorter time.

Another object is to provide a novel set of collapsible dies wherein the finished crankshaft forging with all throws or cranks located at the desired relative angles to eachother, is produced in a single forging operation.

A further object is to provide diesof the. type referred to comprising a plurality of lower dies longitudinally slidable upon the bed plate of a press or the like, and a plurality of complemental upper dies longitudinally' slidably upon the head of thev press, with means for normally spacing said dies longitudinally and means forl moving said, lower and upper dies longitudinally upon contact with cach other.

A still further object is to provide such dies including transversely movable die blocks for forming certain parts of the crankshaft and means for moving said transversely movable die blocks longitudinally with the other die blocks.

It is another objecty of the invention to provide dies. of the character referred to having means, including shouldered rods slidably located through the die blocksr for separating the die blocks longitudinally after 'each forging operation.

A further objectl is to provide such dies having means, including a plunger or ram cooperating with said slidable rods, for moving all of the slidably mounted die blocks into contact with each other.

The above objects together with others, which will be apparent from the drawingsv and following description or which may be later referred to, may be attained by constructing and operating the improved dies in the manner hereinafter described in detail and illustrated inthe accompanying drawings, in which;

Figure 1 isa side elevationl of a formed blank which. is preferably used. inthe improved dies for forging a crankshaft;

Fig. 2 an end elevation. of the blank;

Fig. 3 aside elevation of a conventional crankshaft which. may be forged in the improved dies;

Fig. 4 a side elevation of the improved dies to which the invention pertains showing them in the open position;

Fig.` 5 a side elevation of the dies with the upper dies. in lowered position;

Fig. 6 a side elevation of the dies in completely closed or collapsed position,` with parts broken Briefly the imfention comprises collapsible or y movable forging dies for forming a complete crankshaft having any desired numberv of throws -or cranksl located at the proper angles to each other in a singley forging operation.

For this purpose the invention comprises a.

series of lower dies, normally slightly separated from each other, mounted for longitudinal sliding movement upon the bed or table of a forging press or hammer, certain of the lower dies being also mounted for transverse sliding movement, and a series of complemental upper dies, normally slightly separated from each other and mounted for longitudinal sliding movement upon the vertically movable head or ram of the forging press or hammer, with means for longitudinally moving all of the dies of both the lower and upper series into contact with each other.

Although the improved dies are applicable to the forging of a crankshaft having any desired number of throws or cranks located at any angles to each other which may be desirable or necessary, for the purpose of illustration the dies are shown as designed for forming a conventional type of crankshaft having four thr'ows or cranks which are located at angles of 90 and 180 to each other.

Referring now particularly to the construction of dies illustrated in the accompanying drawings, the bed or table of a forging press or hammer is indicated generally at l and the vertically movable head is indicated at l and adapted to be raised and lowered in conventional manner by any suitable ram means such as one or more pistons Il which may be operated by fluid controlled cylinders of conventional construction.

A series of lower die blocks is mounted for independent longitudinal sliding movement upon the bed or table l5. For this purpose the bed mayhave a box formed thereon comprising the spaced, parallel, longitudinally disposed ribs i3 near opposite sides thereof and the end wall i9 at one end thereof forming a stop for the adjacent endmost lower die block 2li and the complemental upper die block therefor as will be later explained.

The die block 2G, as best shown in Figs. '7 and 1l, has a cavity 2l therein having the portion 22 for forming one-half of a main bearing portion 22a at one end of the crankshaft and the portion 23 for forming a portion of one cheek 23a of a throw or crank.

The next adjacent lower die block 24 has a cavity 25 therein for forming one-half of a crank pin 25a of the crankshaft. The next adjacent lower die block 25 has the cavity 21 therein, having the portion 28 for forming a portion of the other cheek 28a for the pin 25a, a portion 2Q for forming one-half of the main bearing portion 29a of the crankshaft, and the portion 3Q for forming one-half of the cheek Sila of the crankshaft.

A pair of complemental die blocks indicated generally at 3l and 32 are located next in order upon the bed l5, the die block Si being mounted for longitudinal movement only while the die block 32 is mounted for both transverse and longitudinal movement.

For this lpurpose a portion of the adjacent rib i8 of the bed is cut away, as indicated at 33, and the die block 32 is mounted for transverse sliding movement upon the bed Iii by means of any suitable ram or plunger, such as the piston S4 of a fluid operated cylinder,

In order to permit the die block 32 to slide longitudinally upon the bed l5 relative to the plunger 3d, an elongated head 35 is carried by the plunger and provided with a dove tail groove 36 in which is slidably mounted the dove tail lug 31 formed upon the die block 32.

The die block 3| has a cavity 38 in its inner side shaped to form one-half of the crank pin 38a, and the die block 32 has a complemental cavity 39 which forms the other half of said crank pin, and these two dies have the cavity portions d and 6i in opposite sides for forming the opposed side faces of the cheeks 30a and 4lila respectively, which carry the crank pin 38a.

A die block i2 is located upon the bed adjacent to the die blocks 3l and 32 and has a die cavity 53 in its upper face having the portion M which forms substantially one-half or" the cheek Ma of the crankshaft, the portion @l5 which forms onehalf of the main bearing portion a of the crankshaft and the portion 46 which forms substantially one-half of the cheek 46a.

Next to the die block 42 is located a pair of die blocks 4l and t8, similar to the die blocks Si and 32, but reverse in position relative thereto. The die block 4l is mounted for longitudinal sliding movement only upon the bed i5 and has in its inner face a die cavity le shaped to form cnehalf of the crank pin 49a of the crankshaft, and the die block 48 has in its inner face a die cavity 5l) shaped to form the other half of said crank pin.

The die Iblock 8 is mounted for both longitudinal and transverse sliding movement upon the bed l5 and for this purpose the adjacent rib i3 of the bed is cut away as indicated at 5I and this die block has a dove tail lug 52 slidably located within the dove tail groove 53 of the head 54 carried by the plunger 55.

The die block 55, which is mounted for longitudinal movement upon the bed I5 adjacent to the die blocks d? and 48, has the die cavity 5'! in its upper face having the portion 58 for forming one-half of the cheek 58a of the crankshaft, the portion 59 for forming one-half of the crank pin 59a and the portion Si! for forming one-half of the cheek 60a.

The next lower die block 6I has the die cavity 62 therein for forming one-half of the crank pin 62a, and the endmost lower die block 5S has the cavity 8d therein provided with a portion 55 for forming one-half of the cheek 65a and a portion B6 for forming one-half of the end main bearing portion 66a of the crankshaft.

A series of upper dies 6l, 68, 59, le, 1l, T2 and i3 are longitudinally slidably mounted upon the head I6 and located directly above the lower dies 25, 24, 25, 52, 55, 5l and E3 respectively, and have in their under surfaces die cavities complemental to the cavities in said lower dies for forming the other half of the main bearing portions, cheeks and crank pins of the crankshaft.

For the purpose of longitudinally, slidably mounting these upper die blocks in the head i6, a longitudinally disposed dove tail groove M is formed in the under side of the head to receive the dove tail lugs l5 upon the tops of the upper die blocks.

For the purpose of slidably moving all of the lower and upper die blocks longitudinally, to the left as viewed in the drawings, a head 'i6 is provided at the right hand end of the dies, operated by any suitable ram or plunger such as the piston 'il of a uid operated cylinder.

In order to slide the die blocks longitudinally toward the right as viewed in the drawings, to separate them after each operation, a plurality of longitudinally disposed rods F8 and 'I are slidably located through the lower and upper die blocks respectively and provided at properly spaced intervals with shoulders or collars 231)v for engaging the various die blocks and moving them back to the normal open position as shown in Figs. 4 and 5.

The lower rods 18 are slidably located through suitable apertures 8| in the head 'I6 and provided at their outer ends with shoulders or co1- a-,csaava 5,- lars 82 for contacting the outer sidel of thehead and the upper rods 19 are adapted to bey received the grooves 83, open through the top of the head 16, and are also provided with collars or shoulders 84 for engaging they outer side of the head.

The transversely sliding blocks 32 and 48 are provided with transversely disposed horizontal. slots 85 to receive the lower rods 18v and permit sliding movement of these die blocks relative thereto.

Although the crankshaft may be forged in theseV dies from a bar blank of suitable dimensions it is preferable thatra formed blank, such as indicated in Figs. 1 and 2, be produced by rolling or otherwise, this blank havingA spaced pairs of annular enlargements 86 to form the cheeks of the crankshaft with intervening reduced portions 81 for forming the crankV pins, the pairs of enlargements 86 being separated by the portions 88 which form the intermediate main bearing portions of the crankshaft, and the end portions 89 of the blank forming the two main bearing portions at the ends of the crankshaft.

In the operation of the improved dies, with the head I6 raised and the die blocks in the separated position as shown in Fig. 4, the heated blank as shown in Fig. 1, is placed upon the lower die blocks and the head is lowered until the complemental upper and lower die blocks are in contact with each other after which the rams 34 and 55 are operated to move the die blocks 32 and 48 transversely into contact with the complemental die blocks 3| and 41 respectively, forging the two intermediate throws of the crankshaft in a substantially horizontal plane, at an angle of 180 to each other and at angles of 90 to the two endmost throws which have been forged by the lowering of the upper dies.

The ram 11 is then operated to move the head 16 toward the left as viewed in the drawings, moving all of the lower and upper die blocks longitudinally toward the left and into contact with each other as shown in Fig. 1, this last step forging the side faces of the cheeks of the crankshaft and completing the crankshaft forging as shown in Figs. 3 and 7.

When it is desired to return the die blocks to the separated position shown in Fig. 4, the ram 11 is moved in the opposite direction, the head 16 drawing the sliding rods 18 and 19 to the right, the shoulders or collars 80 upon the rods engaging the various die blocks and sliding them to the right, separating them from each other, as shown in Fig. 5.

From the above it will be evident that an improved crankshaft forging is produced with a minimum of labor, as one complete operation of the dies will forge the crankshaft to finished 6' the bed, means for moving said head toward and from the bed, a series of normally separated, independently, longitudinally movable dieblocks carried by the head and corresponding with the die blocks upon the bed to form cooperating pairs of upper and lower die blocks, a pair of transversely disposed die blocks independently longitudinally movable upon the bed, one of said transversely disposedl die blocks being also transversely movable relative to the other, a ram engagirig an endmost die block of each series for moving the die blocks of each series into contact with each other` and4 against the end wall, and means for moving said transversely movable die f block relative to the other transversely disposed die block.

' 2:. Dies for forging a crankshaft comprising a stationary bed, longitudinal ribs at the longitudinal edges of said bed., a transversely disposed wall at one end of the bed, a series of normally separated die blocks independently longitudinally movable upon said bed between the ribs thereon, a vertically movable head. above the bed, means for moving said head toward and from the bed, a series of normally separated, independently, longitudinally movable die blocks carried by the head and corresponding with the die blocks upon the bed to form cooperating pairs of upper and lower die blocks, a pair of transversely disposed die blocks independently longitudinally movable upon the bed, one of said transversely disposed die blocks being also transversely movable relative to the other, a ram engaging an endmost die block of each series for moving the die blocks of each seriesI into contact with each other and against the end wall, and means for moving said transversely movable die block relative to the other transversely disposed die block, longitudinal rods slidably located through each series of dies, spaced shoulders upon said longitudinal rods, and means operatively connecting said lo-ngitudinal rods with said ram for separating the die blocks upon reverse movement of the ram.

3. Dies for forging a crankshaft comprising a stationary bed, longitudinal ribs at the longitudinal edges of said bed, a transversely disposed wall vat one end of the bed, a series of normally separated die blocks independently longitudinally movable upon said bed between the ribs thereon, a vertically movable head abo-ve the bed, means for moving said head toward and from the bed, a series of normally separated, independently, longitudinally movable die blocks carried by the head and corresponding with the die blocks upon the bed. to form cooperating pairs of upper and lower die blocks, at least one cooperating pair of said upper and lower die blocks having their meeting faces located in a plane vertically spaced from the horizontal plane in which the meeting faces of the remainder of said cooperating pairs of upper and lower die blocks are located, a pair of transversely disposed die blocks independently longitudinally movable upon the bed, one o-f said transversely disposed die blocks being also transversely movable relative to the other, a ram engaging an endmost die block of each series for moving the die blocks of each series into contact with each other and against the end wall, and means for moving said transversely movable die block relative to the other transversely disposed die block.

4. Dies for forging a crankshaft comprising a stationary bed, longitudinal ribs at the longitudinal edges of said bed, a transversely disposed wall at one end of the bed, a series of normally 7 separated die blocks independently longitudinally movable upon said bed between the ribs thereon, a vertically movable head above the bed, means for moving said head toward and from the bed, a series of normally separated, independently, longitudinally movable die blocks carried by the head and corresponding with the die blocks upon the bed to form cooperating pairs of upper and lower die blocks, at least one cooperating pair of said upper and lower die blocks having their meeting faces located in a plane vertically spaced from the horizontal plane in which the meeting faces of the remainder of said cooperating pairs of upper and lower die blocks are located, a pair of transversely disposed die blocks independently, longitudinally movable upon the bed, one of said transversely disposed die bloclm being also transversely movable relative to the other, a ram engaging an endmost die block of each series for moving the die blocks of each series into contact 2o with each other and against the end wall, and means for moving said transversely movable die block relative to the other transversely disposed die block, longitudinal rods slidably located through each series of dies, spaced shoulders upon said longitudinal rods, and means operatively connecting said longitudinal rods with said ram for separating the die blocks upon reverse movement'of the ram.

CHARLES A. BRAUCHLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 624,019 Harrington May 2, 1899 1,108,954 Warner Sept. 1, 1914 2,175,156 Mummert Oct. 3, 1939 2,383,356 Walker Aug. 21, 1945 

